This invention claims priority of the German patent application 101 08 989.9 filed Feb. 23, 2001 which is incorporated by reference herein.
The invention refers to a viewing tube for an optical device and in particular for a microscope.
Viewing tubes of the species are generally known. The reader is referred, purely by way of example, to DE 34 32 635 C2, DE 196 22 357 A1, or EP 1 058 141 A2, to which reference is moreover expressly made for an explanation of all terms not described in further detail here.
In the microscopes of the species known from these documents, beam splitters which deflect a portion of the light to a simultaneous observation tube and/or to an imaging or recording unit, for example a photographic camera or a video unit, are provided in the beam path of the viewing tube. Alternatively or additionally, the beam splitters can also reflect into the beam path light from a display and/or processing unit, for example a treatment laser and/or target beam laser. The reader is referred to U.S. Pat. No. 4,138,191 for additional information.
In the known microscopes of the species, multiple beam splitters, each of which is permanently associated with a specific device or a specific task, are therefore provided in succession in the beam path of the viewing tube. Since often not all of the functions that can be performed with these xe2x80x9ccascadedxe2x80x9d beam splitters are needed, the beam splitters provided in succession in the beam path result in a light attenuation that is unnecessary in many applications.
It has therefore been proposed, in a patent application not previously published, to join the beam splitters immovably to the respective device so that in the event of non-use they can be removed from the beam path. But since it is often not necessary to implement all functions simultaneously, the option of being able to mount a variety of devices, each with an associated beam splitter, on the microscope and successively in the beam path increases the overall height.
It is the object of the invention to further develop a viewing tube for an optical device, and in particular for a microscope, in such a way that with no unnecessary attenuation of the light passing through the viewing tube and with no unnecessary increase in the overall height, the various functions, such as reflecting the light out to different units and/or reflecting the light into the respective beam path, can be implemented sequentially in time.
A manner according to the present invention of achieving this object is described herein. Developments of the invention are the subject matter of the dependent claims.
Although a wide variety of functions can be implemented, according to the present invention only a single beam splitter is provided in each beam path of the viewing tube. This guarantees that the overall height of the device is as small as possible. According to the present invention, the beam splitter is rotatable about the optical axis of the respective beam path. The beam splitter thus deflects a portion of the light of the respective beam path in different directions depending on its rotational position. If the different units desiredxe2x80x94such as simultaneous observation tubes, imaging or recording units, display units for presenting images and/or data, and/or units for reflecting light into the beam path of the viewing tubexe2x80x94are then arranged in those different directions, then the various functions desired can be implemented on the basis of the particular rotational position. Not just two, but even three or more functions, and a corresponding number of rotational positions, can be allocated to each beam splitter, while the beam splitter (in contrast to the existing art, in which the beam splitter is replaced and/or displaced) always remains in a functional position in the beam path.
Rotation of the beam splitters introduced into the individual beam paths can be performed in coupled and/or uncoupled fashion. In coupled rotation, actuation of an adjusting element causes both beam splitters to rotate, whereas in uncoupled rotation the beam splitters introduced into the left and right beam paths can be rotated independently of one another.
In a preferred development of the invention the viewing tube has, in a manner known per se, a binocular beam path. In this case it is possible, for example, in one rotational position of the beam splitters to reflect light out of the two beam path segments into a binocular simultaneous observation tube, and in another rotational position to reflect light out of one beam path segment onto an imaging or recording unit and to reflect light into the other beam path segment. The light can be, for example, the light of a display unit or the light of an illumination light source or a processing unit.
In a further preferred embodiment of the invention, each beam splitter has two rotational positions; the two rotational positions can easily be defined by stops, so that the respective beam splitter is exactly adjusted in terms of its rotational position.
A wide variety of beam splitter elements, such as wavelength-selective splitters, polarization splitters, or neutral splitters, such as semitransparent mirrors, and in particular beam splitter cubes, can of course be used as beam splitters.
Use of the viewing tube according to the present invention in a stereomicroscope is especially preferred.
It is additionally possible to combine the basic idea according to the present inventionxe2x80x94of implementing a very wide range of functions by means of only a single beam splitter, introduced into each beam path of the viewing tube, that always remains in its working positionxe2x80x94with the basic ideas that are described in an application submitted on the same date; that application describes the fact that a display module and an imaging module are arranged in stationary fashion on a basic body of an optical device, such as a microscope. Optical connection of the modules to one or both beam paths is accomplished via optical switches that open up or close off the optical paths.